The invention concerns a method and an apparatus for non-intrusive continuous and automatic taking of samples with material and data-like storing of the samples for long-term disposing of the samples and data for a possible evaluation according to criteria which can be defined later on.
The invention generally refers to the field of sampling and storing of samples for the analysis of gasses and liquids as well as sample input into an apparatus for analysis. The invention can for example be applied in investigating a chemical process in a chemical factory, a chemical accident or any other environmental polluting event in retrospection, e.g. the content of a reaction mixture with respect to the main components as a function of time, the contamination of the air in the environment of a depot for chemicals or river water at the places of sewage input. Besides process control and environment control the verification of the non-production of chemical weapons is a potentially important field of application. In case of suspection of a violation of a respective restriction treaty the invention offers a simple possibility of retrospective analysis of samples, which can be exactly related to relevant data like day/time of the sample storage, temperature profiles, pressures and fluxes. An effective continuous sampling and storing of samples for the reason of controlling in the fields mentioned above has not yet been practiced. Recently the lack of a simple, reliable system for sampling and sample storing has become apparent by spectacular chemical accidents.
Many instruments and apparatuses which were employed in former times for the controlling of chemotechnical processes are indeed nowadays used for controlling the environment, the purity of food and the concentration of noxious substances. These instruments for analysis sometimes work continuously but realize the analysis at once in an on-line-operation, that means they do not store samples and correlating data. In exceptional cases liquid or gaseous samples as they are or in an enriched form are applied on sorbents like Tenax or XAD and stored until analysis is performed. For this purpose there are sample collectors and auto injectors for gas chromatography on the market, the latter for the automatic input of the sorbed chemical components into an instrument for analysis, for example into a combination of a gas chromatograph and mass spectrometer.
A multiple passive probe collector with the possibility of fast input of the sample into the input head of an instrument for analysis has been described as an advantageous alternative to Tenax- and XAD-sorption tubes (DE-A 3,137,765 and U.S. Pat. 4,541,268). Here the ability of an sorptive collecting plate for sample enriching, sample storage and sample desorption after transfer to the heated input head of a mass spectrometer or any other instrument for analysis is used. As sorbent for example a silicone membrane can be used.
Moreover an automatic system for clinical-chemical laboratories called "SILAB" has been published in the periodical Siemens-Zeitschrift, No. 5 of May 1973. The field of application of "SILAB" touches the biological-chemical analyzing and evaluating of the results at the point, where so-called laboratory automats are used.
Sampling and evaluating are closely connected with respect to the time in this case. Each analysis is evaluated and it is the declared purpose to accelerate the medical diagnostics by means of mechanization and rationalization including the use of data processing (at the state of the art of 1973) and to meet the demands of an increasing number of necessary examinations. The biological substances that are to be examined are usually perishable, which means chemical-biological changing, and, therefore, must be brought to the examination in short time intervals. The durability of each sample is very limited, but because of apt vessels for the examinations (e.g. for blood and serum) a relatively large space is required.
The automatic system "SILAB" works only according to a discontinuous machining cycle which must be defined in advance for special samples, in a close time connection to a given equipment and using given evaluation criteria. The advantages lie only in rationalization and rise of the output of the required chemical-clinical laboratory works.
The techniques according to the state of the art are consumptuous with respect to the space requirements, the costs for producing and operating and with respect to the personnel requirements. Furthermore, they are hardly fully automatized and subject to disturbations. The correlation between certain relevant data associated with a sample, e.g. day, time, temperatures, pressures, flux-rates, etc. is connected with a consumptuous protocolling and therefore subject to error. Moreover, the correlation of the data can easily be manipulated. Sample analysis is often time-consuming and difficult, whereby the information of interest about the sample has to be selected out of a variety of undesired data which are either irrelevant with respect to the analytical questions or even secret.
Until now no simple automatic sampling method has been published which would be apt to detect in case of need one or more chemical components in a gas or liquid mixture subsequently and with exact correlation to relevant data of the sampling like time, temperatures, etc.